The invention relates to a device for advancing rod-shaped workpiece material in a cutting machine in the form of a hacksaw, circular cold, saw or the like, in which during the cutting operation the material supported on a table of the cutting machine is held by at least one pair of clamping jaws that can be opened and closed and that are immovably arranged in front of the cutting plane in the material advance direction and by a pair of advancing jaws which are arranged after the cutting plane and can be displaced in the material advance direction, with at least one jaw being transversely movable for the purpose of opening and closing, and by means of which, after the separating cut has been made, the severed material can be removed in the material advance direction to a deposition station and by means of which, passing through the cutting plane, the unworked material can be grasped afresh and can be advanced when the clamping jaws are open.
Such a device is known from German Patent Specification No. 28 16 497, in which, in a widely used manner, a feed device for the material is arranged upstream of the table of the cutting machine, this feed device being, for example, in the form of a roller conveyor which also supports the material being worked.
In the case of the known device it was possible, and provision was made, to remove the severed material from the cutting machine with the aid of the advancing jaws, for which purpose each severed piece of material could be transported in the material advance direction by the advancing jaws from the cutting plane to a point, the position of which could be predetermined, where the piece of material could be released and thus deposited. After the advancing jaws had returned to their cutting position in the cutting machine, the piece of material could then be moved from the deposited position to a further processing operation. However, this construction requires the entire device, including the material feed means, the accommodation of which is often possible only with difficulty and is therefore reluctantly accepted, to be of considerable overall length in the material advance direction. On the other hand, it is necessary to supply severed pieces of material, which may be of different sizes, to further processing steps, which may also vary. In the known device, this could be taken into account by the fact that when the material was removed from the cutting machine the pieces of material were moved by the advancing jaws in the material advance direction to different positions from which they could then pass on to various forms of further processing. However this therefore necessitated further enlargement of the device in the material advance direction and in this case, as in the case described above, it was often additionally necessary for material that had been severed and positioned at a distance from the cutting machine to be moved out of the way immediately, for example through the provision of a deposition station of adjustable height, so that there was sufficient space for the material subsequently advanced. This also gave rise to increased expenditure.
The disclosure sets forth a device of the type mentioned at the beginning in such a manner that the removal of material from the cutting machine no longer requires the device to be lengthened in the material advance direction also it does not require the deposition station for the severed material to be of adjustable height. If this construction is retained, however, the severed material may be positioned in such a manner that it lies outside the path of the material in the advance direction. The further development should essentially make use of the existing means of the device and should be capable of being accommodated within the space that is in any case available, that is to say it should be realised without additional space being required and with simple supplementary means.
Starting from a device of the type mentioned at the beginning, this problem is solved according to the invention by the fact that one transversely movable advancing jaw can be displaced beyond the other advancing jaw and that the other advancing jaw can be moved out of this displacement path and out of the corresponding lateral displacement path of the severed material.
As a result of these simple measures it is possible to move each severed piece of material directly sideways, without further movement in the material advance direction, to a space which is in any case available as a result of the customary dimensions of a cutting machine. To this end, it is necessary merely to enlarge the range of movement of the transversely movable advancing jaw in such a manner that, after the transverse displacement of the severed material, the two advancing jaws are again free to move parallel to the material advance direction. In order that the severed material can be moved transversely, the other advancing jaw is removed for a short distance in order to clear the way.
For this purpose, the other advancing jaw can be displaceably arranged on vertical guides. It is equally possible, however, to arrange the other advancing jaw in such a manner that it can be swivelled away either about an axis arranged transversely with respect to the material advance direction or about an axis arranged parallel to the material advance direction, it being advantageous for the other advancing jaw to be pivotable between stops, which may be adjustable.
It has proved to be especially advantageous for the other advancing jaw to be able to swivel upwards, especially in conjunction with a type of construction that is distinguished by the fact that the advancing jaws are displaceably or pivotably arranged on a carriage that extends above and across the material advance path, and that the carriage can be displaced along a guideway that extends parallel to the material advance direction and is arranged on the side of the one, transversely movable advancing jaw remote from the material. There is thus provided a type of construction which can move substantially freely above the surface supporting the material, so that, also in structural terms, it is essentially possible for there to be a separation between the means providing this support surface on the one hand and the carriage for accommodating the advancing jaws, including their adjusting devices, on the other hand.
As is known, the advancing jaws are so arranged or constructed that their vertical edges facing the cutting machine are in alignment transverse to the material advance direction. On the other side of the advancing jaws it has proved advantageous, however, for the clamping surface of the one, transversely movable advancing jaw to be extended in the material advance direction away from the cutting plane. As a result, there is a broad contact surface for the material, especially for effecting its transverse movement, so that the material cannot tilt.
In a further development of the subject of the invention it has proved advantageous for the other advancing jaw to be displaceable into the material advance path by a small amount transverse to the material advance direction. This gives rise to the possibility of using the other advancing jaw simultaneously as a stop and thus for the initial positioning of newly inserted rod material, so that the separate stop that is customarily used for this purpose can be dispensed with.
All the described movements of the advancing jaws on the carriage are advantageously carried out hydraulically by means of cylinder piston units, since the pressure medium required for this purpose is usually in any case available in cutting machines.
Furthermore, it is advantageous for the advancing jaws to be displaceable by means of the carriage in such a manner that, after the material advance, that is to say after the next piece of material to be cut off has been pulled forward, the jaws can be returned to the middle of this piece of material to be cut off and can there be clamped onto the material. As a result, on the one hand this piece of material is held in a favourable position for the cutting operation that is to be carried out and, on the other hand, it is positioned equally favorably for the transverse displacement to be effected after cutting.
In view of this transverse displacement, it is finally advantageous for a material support table adjoining the table of the cutting machine in the material advance direction to be widened at least by an amount corresponding to the amount by which the severed material can be displaced transversely by means of the transversely movable advancing jaw. This widened portion can be arranged to be horizontal but can equally be constructed, for example, as an inclined surface over which the material rolls or slides downwards. The term "table" is intended to cover any design possibly performing other functions, and thus, for example, includes also a construction in the form of a roller conveyor, a surface with openings, or the like.